Generic List to CSV String

c#, linq, list

Solution

Your method can be simplified using `StringBuilder` and `string.Join`.

Concatenating strings directly is slow and uses a lot of memory which is fine for small operations.

See: Does StringBuilder use more memory than String concatenation?

private static string CreateCSVTextFile<T>(List<T> data, string seperator = ",")
{
    var properties = typeof(T).GetProperties();
    var result = new StringBuilder();

    foreach (var row in data)
    {
        var values = properties.Select(p => p.GetValue(row, null));
        var line = string.Join(seperator, values);
        result.AppendLine(line);
    }

    return result.ToString();
}

A more complete implementation for CSVs:

private static string CreateCSVTextFile<T>(List<T> data)
{
    var properties = typeof(T).GetProperties();
    var result = new StringBuilder();

    foreach (var row in data)
    {
        var values = properties.Select(p => p.GetValue(row, null))
                               .Select(v => StringToCSVCell(Convert.ToString(v)));
        var line = string.Join(",", values);
        result.AppendLine(line);
    }

    return result.ToString();
}

private static string StringToCSVCell(string str)
{
    bool mustQuote = (str.Contains(",") || str.Contains("\"") || str.Contains("\r") || str.Contains("\n"));
    if (mustQuote)
    {
        StringBuilder sb = new StringBuilder();
        sb.Append("\"");
        foreach (char nextChar in str)
        {
            sb.Append(nextChar);
            if (nextChar == '"')
                sb.Append("\"");
        }
        sb.Append("\"");
        return sb.ToString();
    }

    return str;
}

Using: escaping tricky string to CSV format

Problem

Original source

Related problems

• escaping tricky string to CSV format
• Does StringBuilder use more memory than String concatenation?